Preheat oven to 375F.
In a medium mixing bowl, combine the dry ingredients – the flour, salt, baking soda, and cocoa powder.
Separately in a large mixing bowl, combine the wet ingredients – the shortening, sugar, brown sugar, vanilla, Nutella, and egg.
Add the dry ingredients to the wet and stir to incorporate. Add the walnuts, M&Ms, and chocolate morsels.
Using 2 spoons or a cookie scoop, scoop out ~1½-in mounds onto a large baking sheet. Bake at 375F for 10-12 minutes until just toasted around the edges. Take cookies out of the oven and let them cool 2 minutes, then gently transfer them to a cooking rack so they can cool completely.